ergo
template_blas_swap.h
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1 /* Ergo, version 3.8, a program for linear scaling electronic structure
2  * calculations.
3  * Copyright (C) 2019 Elias Rudberg, Emanuel H. Rubensson, Pawel Salek,
4  * and Anastasia Kruchinina.
5  *
6  * This program is free software: you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation, either version 3 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program. If not, see <http://www.gnu.org/licenses/>.
18  *
19  * Primary academic reference:
20  * Ergo: An open-source program for linear-scaling electronic structure
21  * calculations,
22  * Elias Rudberg, Emanuel H. Rubensson, Pawel Salek, and Anastasia
23  * Kruchinina,
24  * SoftwareX 7, 107 (2018),
25  * <http://dx.doi.org/10.1016/j.softx.2018.03.005>
26  *
27  * For further information about Ergo, see <http://www.ergoscf.org>.
28  */
29 
30  /* This file belongs to the template_lapack part of the Ergo source
31  * code. The source files in the template_lapack directory are modified
32  * versions of files originally distributed as CLAPACK, see the
33  * Copyright/license notice in the file template_lapack/COPYING.
34  */
35 
36 
37 #ifndef TEMPLATE_BLAS_SWAP_HEADER
38 #define TEMPLATE_BLAS_SWAP_HEADER
39 
40 
41 template<class Treal>
42 int template_blas_swap(const integer *n, Treal *dx, const integer *incx,
43  Treal *dy, const integer *incy)
44 {
45  /* System generated locals */
46  integer i__1;
47  /* Local variables */
48  integer i__, m;
49  Treal dtemp;
50  integer ix, iy, mp1;
51 /* interchanges two vectors.
52  uses unrolled loops for increments equal one.
53  jack dongarra, linpack, 3/11/78.
54  modified 12/3/93, array(1) declarations changed to array(*)
55  Parameter adjustments */
56  --dy;
57  --dx;
58  /* Function Body */
59  if (*n <= 0) {
60  return 0;
61  }
62  if (*incx == 1 && *incy == 1) {
63  goto L20;
64  }
65 /* code for unequal increments or equal increments not equal
66  to 1 */
67  ix = 1;
68  iy = 1;
69  if (*incx < 0) {
70  ix = (-(*n) + 1) * *incx + 1;
71  }
72  if (*incy < 0) {
73  iy = (-(*n) + 1) * *incy + 1;
74  }
75  i__1 = *n;
76  for (i__ = 1; i__ <= i__1; ++i__) {
77  dtemp = dx[ix];
78  dx[ix] = dy[iy];
79  dy[iy] = dtemp;
80  ix += *incx;
81  iy += *incy;
82 /* L10: */
83  }
84  return 0;
85 /* code for both increments equal to 1
86  clean-up loop */
87 L20:
88  m = *n % 3;
89  if (m == 0) {
90  goto L40;
91  }
92  i__1 = m;
93  for (i__ = 1; i__ <= i__1; ++i__) {
94  dtemp = dx[i__];
95  dx[i__] = dy[i__];
96  dy[i__] = dtemp;
97 /* L30: */
98  }
99  if (*n < 3) {
100  return 0;
101  }
102 L40:
103  mp1 = m + 1;
104  i__1 = *n;
105  for (i__ = mp1; i__ <= i__1; i__ += 3) {
106  dtemp = dx[i__];
107  dx[i__] = dy[i__];
108  dy[i__] = dtemp;
109  dtemp = dx[i__ + 1];
110  dx[i__ + 1] = dy[i__ + 1];
111  dy[i__ + 1] = dtemp;
112  dtemp = dx[i__ + 2];
113  dx[i__ + 2] = dy[i__ + 2];
114  dy[i__ + 2] = dtemp;
115 /* L50: */
116  }
117  return 0;
118 } /* dswap_ */
119 
120 #endif
template_blas_swap
int template_blas_swap(const integer *n, Treal *dx, const integer *incx, Treal *dy, const integer *incy)
Definition: template_blas_swap.h:42
integer
int integer
Definition: template_blas_common.h:40